In this paper we present
a theoretical and experimental study of the self-excited walking of a
biped mechanism with knees and feet on level ground. This biped mechanism
possesses a single motor at the hip joint and active lock mechanisms at
both knee joints.We first show that the self-excitation control enables
the three-degrees-of-freedom planar biped model with feet to walk on level
ground, and that a stable walking locomotion is possible over a wide range
of feedback gain and a foot radius of up to 0.3 m. Subsequently, we describe
the manufactured biped Robot 2 which is similar to the analytical model
and we show that the biped robot can perform natural dynamic walking on
a level floor. It is also shown that the simulated results agree well
with the experimental results. We further describe the wireless-controlled
biped Robot 3, which can walk on a level floor carrying batteries and
electronic circuits inside the thighs.